Answer: m = 0.035kg = 35g
Explanation: Momentum p=0.140kgm/s
Velocity v=4m/s
Mass m=?
Formula-
Momentum depends on the mass of the object in motion and its velocity.
The equation for momentum is
p = mv
m = p/v
m = 0.140/4
m = 0.035kg
m = 35g
Hence, in the toy dart gun mass of the dart is 0.035kg.
Answer : The average speed of the sprinter is, 34.95 Km/hr
Solution :
Average velocity : It is defined as the distance traveled by the time taken.
Formula used for average velocity :

where,
= average velocity
d = distance traveled = 200 m
t = time taken = 20.6 s
Now put all the given values in the above formula, we get the average velocity of the sprinter.

conversion :
(1 Km = 1000m)
(1 hr = 3600 s)
Therefore, the average speed of the sprinter is, 34.95 Km/hr
Answer: 2200J
Explanation:
M = 44kg
V = 10m/s
K.E =?
K.E = 1/2MV2 = 1/2 x 44 x (10)^2
K.E = 22 x 100
K.E = 2200J