Answer:
The frictional force needed to overcome the cart is 4.83N
Explanation:
The frictional force can be obtained using the following formula:

where
is the coefficient of friction = 0.02
R = Normal reaction of the load =
=
= 
Now that we have the necessary parameters that we can place into the equation, we can now go ahead and make our substitutions, to get the value of F.

F = 4.83 N
Hence, the frictional force needed to overcome the cart is 4.83N
Answer:
(a) 62.5 m
(b) 7.14 s
Explanation:
initial speed, u = 35 m/s
g = 9.8 m/s^2
(a) Let the rocket raises upto height h and at maximum height the speed is zero.
Use third equation of motion


h = 62.5 m
Thus, the rocket goes upto a height of 62.5 m.
(b) Let the rocket takes time t to reach to maximum height.
By use of first equation of motion
v = u + at
0 = 35 - 9.8 t
t = 3.57 s
The total time spent by the rocket in air = 2 t = 2 x 3.57 = 7.14 second.
Answer:

Explanation:
The free body diagram of the block on the slide is shown in the below figure
Since the block is in equilibrium we apply equations of statics to compute the necessary unknown forces
N is the reaction force between the block and the slide
For equilibrium along x-axis we have

Using value of N from equation β in α we get value of force as

Applying values we get
