Answer:
3.83 m/s
Explanation:
Given that,
Distance covered by Jan, d = 4 miles
1 mile = 1609.34 m
4 miles = 6437.38 m
Time, t = 28 minutes = 1680 s
Jan's average speed,
v = d/t

Hence, the average velocity of Jan is 3.83 m/s.
Explanation:
Given:
Solving for
:

where:

Integrating to get
with initial conditions
:

Integrating to get x with initial conditions x(0) = 0:

When t=T:


Answer:
10259.6 m
Explanation:
We are given that
Radius of small wheel,r=0.17 m
Radius of large wheel,r'=0.92 m
Initial velocity,u=0
Time,t=2.7 minutes=162 s
1 min=60 s
Velocity,v=10m/s
Time,t'=13.7 minutes=822 s
Time,t''=4.1 minutes=246 s

Substitute the values



Substitute the values




Total distance traveled by rider=s+s'+s''=809.6+8220+1230=10259.6 m
Answer:
The work done on the Frisbee is 1.36 J.
Explanation:
Given that,
Mass of Frisbee, m = 115 g = 0.115 kg
Initial speed of Frisbee, u = 12 m/s at a point 1 m above the ground
Final speed of Frisbee , v = 10.9674 m/s when it has reached a height of 2.00 m. Let W is the work done on the Frisbee by its weight. According to work energy theorem, the work done is equal to the change in its kinetic energy. So,

So, the work done on the Frisbee is 1.36 J. Hence, this is the required solution.
Answer:
Option (b) is correct.
Explanation:
The motion under the influence of gravity is called projectile motion.
The acceleration due to gravity is constant through out the motion and it is always acting downwards.
When an athlete jumps and follow the projectile path, it always have the same horizontal velocity as there is no acceleration in the horizontal direction.
Also he has the vertical acceleration constant which is equal to the acceleration due to gravity and acts towards the center of earth.
Option (b) is correct.