when the ball hits the floor and bounces back the momentum of the ball changes.
the rate of change of momentum is the force exerted by the floor on it.
the equation for the force exerted is
f = rate of change of momentum

v is the final velocity which is - 3.85 m/s
u is initial velocity - 4.23 m/s
m = 0.622 kg
time is the impact time of the ball in contact with the floor - 0.0266 s
substituting the values

since the ball is going down, we take that as negative and ball going upwards as positive.
f = 189 N
the force exerted from the floor is 189 N
Answer:
You pull on the oars. By the third law, the oars push back on your hands, but that’s irrelevant to the motion of the boat. The other end of each oar (the blade) pushes against the water. By the third law, the water pushes back on the oars, pushing the boat forward.
+ 1.58 e -15
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Answer:
a)KE=878.8 J
b)W=2636.4 J
Explanation:
Given that
mass ,m = 65 kg
Initial speed ,u = 5.2 m/s
a)
We know that kinetic energy KE is given as follows

m=mass
u=velocity
Now by putting the values in the above equation we get

KE=878.8 J
b)
We know that
Work done by all forces = Change in the kinetic energy
The final velocity , v= 2 u = 2 x 5.2 m/s
v= 10.4 m/s

Now by putting the values in the above equation we get

W=2636.4 J
a)KE=878.8 J
b)W=2636.4 J
Answer:
Rs. 480.00
Explanation:
1kW = 1000W
therefore 500W = 0.5kW
20 × 24hrs = 480hrs in total.
0.5kW × 480hrs = 240kWh
if rs. 2 for 1kWh
then, 240kWh × 2 = Rs. 480.