# Calculus

1.if a ball is thrown into the air with a velocity of 35ft/s, it's height in feet after t seconds is given by y=35t-10t^2. Find the averag velocity for the time period beginning when t=4 and lasting 0.05s.
2.if a ball is thrown into the air with a velocity of 30ft/s, it's height in feet after t seconds is given by y=30t-20t^2. Find the instantaneous velocity when t=3

1. 👍 0
2. 👎 0
3. 👁 145
1. Last time I was on this earth, gravity would cause an equation of the type
y = -16t^2 .....
So assuming you have a typo and it should have been
y = 35t - 16t^2
Second problem:
the ball would not be in the air for 4 seconds,
so your whole first question is actually just gibberish.
Once you fix it, find y when t = 4
find y when t = 4.05
evaluate: ( y(4.05) - y(4) )/.05

2. same thing here,
after 3 seconds the ball has reached the ground, and no longer has any velocity

if we ignore reality,
dy/dt = 30 - 40t
when t = 3
dy/dt = 30 - 120 = -90 ft/s

1.
when t=4, y = 35(4) - 16(16) = -20

1. 👍 0
2. 👎 0
posted by Reiny
2. There is no error in the problem.

1. 👍 0
2. 👎 0
posted by Jacke
3. I see the typo as specifying feet. In metric units, g=9.8, or roughly 10, so Jacke, redo the calculations, with g=10 and get the correct answer.

1. 👍 0
2. 👎 0
posted by Steve
4. Is it ok if I get a negative answer???

1. 👍 0
2. 👎 0
posted by Jacke
5. OK thanks I got it

1. 👍 0
2. 👎 0
posted by Jacke

## Similar Questions

1. ### algebra

A ball is thrown into the air with an upward velocity of 40 feet per second. Its height, h, in feet after t seconds is given by the function h(t)=-16t^2+40t+10. a. What is the ball’s maximum height? 35Ft b. When the ball hits

asked by Hannah on January 7, 2018
2. ### Math

In high school, I played soft ball. I hit the ball into the air with an upward velocity of 35 ft. The equation that gives the height (h) of the ball at any time (t) is: h(t)= -15t2 + 35ft + 1.0. What is the y-coordinate of the

asked by Kendra on April 29, 2016
3. ### Math

The height(H) of an object that has been dropped or thrown in the air is given by: H(t)=-4.9t^2+vt+h t=time in seconds(s) v=initial velocity in meters per second (m/s) h=initial height in meters(m) H=height h=initial height I

asked by Anonymous on April 4, 2012
4. ### Math

The height(h) of an object that has been dropped or thrown in the air is given by: h(t)=-4.9t^2+vt+h t=time in seconds(s) v=initial velocity in meters per second (m/s) h=initial height in meters(m) A ball is thrown vertically

asked by NeedHelp on April 4, 2012
5. ### Math Help (URGENT X10)

This is really urgent so please please please help. The height(H) of an object that has been dropped or thrown in the air is given by: H(t)=-4.9t^2+vt+h t=time in seconds(s) v=initial velocity in meters per second (m/s) h=initial

asked by Anonymous on April 4, 2012
6. ### College algebra

When a ball is thrown up into the air, it makes the shape of a parabola. The equation S= -5t^2 + v*t + k gives the height of the ball at any time, t in seconds, where “v” is the initial velocity (speed) in meters/sec and

asked by Dimpleface on June 16, 2010
7. ### physics

A ball is thrown vertically upwards with an initial velocity of 20.96 m/s. Neglecting air resistance, how long is the ball in the air? What is the greatest height reached by the ball? this problem seems easy enough but I can't

asked by courtney on January 16, 2008
8. ### physics

A ball is thrown vertically upwards with a velocity of 2 m/s. It is seen at height h twice. Find the sum of the times, measured in seconds from the moment the ball is thrown, at which it is seen at height h. Take g=10m/s² Neglect

asked by un on June 9, 2017
9. ### Calculus 1

A ball is thrown vertically upward from ground level with initial velocity of 96 feet per second. Assume the acceleration of the ball is a(t) = -32 ft^2 per second. (Neglect air Resistance.) (a) How long will it take the ball to

asked by Bobby on December 3, 2018
10. ### math

The height h, in feet, of a ball above the ground t seconds after being thrown upward with a velocity of 48 ft/s is given by . After how many seconds will the ball be 35ft above the ground?

asked by mathman on September 13, 2012

More Similar Questions