# physics

posted by amy

The acceleration of a particle moving only on a horizontal plane is given by a= 3ti +4tj, where a is in meters per second-squared and t is in seconds.
At t = 0s, the position vector r= (20.0 m)i + (40.0 m)j locates the particle, which then has the velocity vector v= (5.000 m/s)i + (2.00 m/s)j

(a) What is the expression of its instantaneous velocity vector, as a function of time?
(b) What is the expression of its instantaneous position vector, as a function of time?

At t = 4s, what are :

(c) its position vector in unit-vector notation?
(d) the angle between its direction of travel and the positive direction of the x axis?

## Similar Questions

1. ### Physics

The position vector r of a particle moving in an xy plane is given by [r = (6t^3-3t)i + (4-1t^4)j] with r in meters and t in seconds. What is the angle between the positive direction of the x axis and a line tangent to the particle's …
2. ### physics

The acceleration of a particle moving only on a horizontal plane is given by a= 3ti +4tj, where a is in meters per second-squared and t is in seconds. At t = 0s, the position vector r= (20.0 m)i + (40.0 m)j locates the particle, which …
3. ### Physics

The vector position of a 3.45 g particle moving in the xy plane varies in time according to 1 = 3 + 3t + 2t2 where t is in seconds and is in centimeters. At the same time, the vector position of a 5.00 g particle varies as 2 = 3 − …
4. ### Physics

The vector position of a 3.45 g particle moving in the xy plane varies in time according to 1 = 3 + 3t + 2t2 where t is in seconds and is in centimeters. At the same time, the vector position of a 5.00 g particle varies as 2 = 3 − …
5. ### Physics

A particle moved along the x axis with a constant acceleration of -85.0 meters per second squared. The initial position of the particle was at the origin and its initial velocity was +325 meters per second. Find the position of the …
6. ### Calculus

The position of a particle moving on a horizontal line is given by s(t)=2t^3-15t^2+24t-5, where s is measured in feet and t in seconds. a: What is the initial position of the particle?
7. ### physics

The position vector r of a particle moving in the xy plane is r=2ti+2sin[(pi/4)t]j , with is in meters and t in seconds. (a) Calculate the x and y components of the particle's position at , and 4.0 s and sketch the particle's path …
8. ### Physics

The acceleration of a particle moving only on a horizontal xy plane is given by , where is in meters per second-squared and t is in seconds. At t = 0, the position vector locates the paticle, which then has the velocity vector . At …
9. ### Physics

The acceleration of a particle moving only on a horizontal xy plane is given by a=5ti+6tj, where a is in meters per second-squared and t is in seconds. At t=0, the position vector r=(19.0m)i+(39.0m)j locates the particle, which then …
10. ### Physics

The acceleration of a particle moving only on a horizontal xy plane is given by a=5ti+6tj, where a is in meters per second-squared and t is in seconds. At t=0, the position vector r=(19.0m)i+(39.0m)j locates the particle, which then …

More Similar Questions