Question

1) As a raindrop falls through the atmosphere, its speed initially changes as it falls toward the Earth. Before the raindrop reaches its terminal speed, the magnitude of its acceleration A. increases B. decreases C. stays constant at zero D. stays constant at 9.8 m/s? E. stays constant at a value not equal to zero nor 9.8 m/s2 The position vector of a particle is given by r(t) = 2tî + 3t2ġ where ř is measured in metres and t is measured in seconds. Given that the mass of the particle is 0.5 kg, calculate the linear momentum of the particle at t = 2 s. A. (129) kg m/s B. (î + 6ſ) kg m/s C. (2î + 6j) kg m/s D. (4î + 12j) kg m/s 3) A 200 g block is placed on a rough horizontal surface as shown in the figure below. A 4-N force is applied on the block at an angle of 30° with the horizontal axis. Given that the static coefficient of friction between the block and the surface is 0.9 and the kinetic coefficient of friction is 0.7, what is the value of the frictional force acting on the block? 30° A. 1.8 N B. 1.4 N C. 2.8 N D. 3.5 N 4) A truck loaded with sand accelerates along a highway. The driving force on the truck remains constant. What happens to the acceleration of the truck if its trailer leaks sand at a constant rate through a hole in its bottom? A. It decreases at a steady rate. B. It increases at a steady rate. C. It increases and then decreases. D. It decreases and then increases. E. It remains constant.

Answer 1

Answer:-

1) B) decrease

2) C);(2i +6 j) kgm/s

3) d) 3.5 N

4) b) It increase at steady rate