# physics

posted by .

A boy throws a rock with an initial velocity of 2.47 m/s at 30.0 degrees above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory?

• physics -

Just do the vertical problem
Vi = 2.47 sin 30 = 1.23 m/s

v = Vi - 4.9 t
at top, v = 0
0 = 1.23 - 4.9 t
solve for t

## Similar Questions

1. ### Physics

A man stands on the roof of a 19.0 m-tall building and throws a rock with a velocity of magnitude 24.0 m/s at an angle of 38.0 degrees above the horizontal. You can ignore air resistance. Calculate the maximum height above the roof …
2. ### physics

Consider a rock that is thrown off a bridge of height 27 m at an angle θ = 24° with respect to the horizontal as shown in the figure above. If the initial speed the rock is thrown is 12 m/s, find the following quantities: (a) …
3. ### College Physics

Consider a rock thrown off a bridge of height 78.5 m at an angle è = 25° with respect to the horizontal as shown in Figure P4.20. The initial speed of the rock is 15.6 m/s. Find the following quantities: (a) the maximum height reached …
4. ### Physics

A man stands on the roof of a building that is 50 m tall and throws a rock with a velocity of 35 m/s at an angle of 50 degrees above the horizontal (a) What is the total time in the air (b) What is the horizontal distance from the …
5. ### Calculus Help Please!!! Check

If a rock is propelled upward from the surface of Mars at a velocity of 93 m/sec, it reaches a height s = 93t – 1.86t^2 after t sec. a. Find the rock’s velocity and acceleration at time t. v'(t)=93-3.72t a''(t)=-3.73 b. How long …
6. ### Calculus Help Please!!! Check

If a rock is propelled upward from the surface of Mars at a velocity of 93 m/sec, it reaches a height s = 93t – 1.86t^2 after t sec. a. Find the rock’s velocity and acceleration at time t. v'(t)=93-3.72t a''(t)=-3.73 b. How long …
7. ### Physics

A boy throws a rock with an initial velocity of 1.67 m/s at 30.0° above the horizontal. If air resistance is negligible, how long does it take for the rock to reach the maximum height of its trajectory?
8. ### physics

a person uses a slingshot to launch a rock upward with a velocity of 30m/s how long does it take to reach a height of 20m what maximum height does the rock reach, what is the velocity of the rock at this height, what is the velocity …
9. ### physics

a boy uses a slingshot to launch a rock with a velocity of 30m/s how long does it take it to reach a height of 20m,what maximum height does the rock reach, what is the velocity of the rock at this height, what is the velocity of the …
10. ### physics

a boy uses a sling shot to launch a rock upward with a velocity of 30m/s how long does it take to reach a height of 20 m what maximum height does the rock reach, what is the velocity of the rock at this height, what is the velocity …

More Similar Questions