Answer
given,
initial speed of hockey player= 0 m/s
mass of the helmet, m = 1.3 Kg
initial speed of the helmet, u = 0 m/s
final speed of the helmet, v = 6 m/s
recoil speed of the hockey player, v' = 0.25 m/s
we need to calculate the mass of the hockey player, M = ?
using conservation of momentum
m u + M u' = M v' + m v
initial speed of ice skater is zero
1.3 x 0 + M x 0 = M x (-0.25) + 1.3 x 6
negative sign is taken because recoil velocity is in opposite direction
0 = -0.25 M + 7.8
0.25 M = 7.8
M = 31.2 Kg
Hence, the mass of the young hockey player is equal to 31.2 Kg
Answer:
Answer is
A. I = 6.3×10^8 A
B. Yes
C. No
Refer below.
Explanation:
Refer to the picture for brief explanation.
1. Answer: A skydiver whose air resistance is equal to that of her weight.
A skydiver free falls under gravity but her rate of fall slows down due to drag -air resistance. when this air resistance becomes equal to her weight, the two get balanced and the body does not accelerate or decelerates.
2. Answer: Gravity
Contact forces are those which act when there is physical contact between two bodies. For example: normal force, tension and spring force.
Non-contact forces act between two bodies even when they are at a distance apart. For example: gravity, electric force, magnetic force etc.
3. Answer: The tendency of an object's motion to remain the same.
Inertia is a property of matter by virtue of which it tends to remain in its state of motion or rest. It does depend on mass of the object, more the mass, more is inertia. For example, cycle can be easily moved but we need real push hard for a car to move.
4. Answer: 254 N
The man pushes the box with 310 N force at an angle of 55 degrees to the horizontal.
we can write this in terms of horizontal (
)and vertical component (
).
Horizontal component: 
Vertical component: 
The vertical component would act towards the floor making the job more difficult to move the job.
Wind, radiation, and the sun are all factors that change the temperature.
Solar heating of the Earth's surface is uneven because land heats faster than water, and this causes air to warm, expand and rise over land while it cools and sinks over the cooler water surfaces.
I don’t think so because an ice cube melting needs heat and relies on temp while ooblecks transition from solid to quickly depends on force and speed