Answer:
option (c) 
Explanation:
When an object thrown upwards, the value of acceleration acting on the object is acceleration due to gravity which is always acting towards the earth. 
As it falls downwards, the acceleration is again equal to the acceleration due to gravity. 
So, the ball's acceleration is constant. 
 
        
             
        
        
        
Answer:
E. 3h
Explanation:
We know that
u = 0 m/s. 
velocity after t = 1s
v = u+gt = 0+9.81 x 1s= 9.81 m/s
distance covered in 1st sec
 = =>> ut+0.5 x g x t²
=>>0 + 0.5x 9.81 x 1 = 4.90m 
Let 4.90 be h
distance travelled in 2nd second will now be used
So velocity after t = 1s
=>>1 x t+ 0.5 x g x t² 
=>9.81x 1 + 0.5 x 9.81 x 1 = 3 x 4.90 
 So since h= 4.90
Then the ans is 3x h = 3h
 
        
             
        
        
        
Answer:

T=157.06 N
Explanation:
Given that 
Mass of first block = 21.1 kg
Mass of second block = 12.9 kg
First mass is heavier than first that is why mass second first will go downward and mass second will go upward.
Given that pulley and string is mass  less that is why both mass will have same acceleration.So lets take their acceleration is 'a'.
So now from force equation

21.1 x 9.81 - 12.9 x 9.81 =(21.1+12.9) a

Lets tension in string is T


T=21.1(9.81-2.36) N
T=157.06 N
 
        
             
        
        
        
Answer:
       R = 8.01 m
Explanation:
We can solve this problem using the projectile launch equations. The jump length is the throw range
            R = v₀² sin  2θ / g
in the exercise they give us the initial speed of 9.14 m / s and in the launch angle 35º
let's calculate
            R = 9.14² sin (2  35) / 9.8
            R = 8.01 m
this is the jump length