Answer:
D. x-rays
Explanation:
Lower frequency: Radio waves, microwaves and infrared have lower frequency than visible light. Shorter wavelength: Ultraviolet, x-rays and gamma rays have a shorter wavelength than visible light.
Answer:C
Explanation:
When a constant horizontal force is applied to the box, box started moving in the horizontal direction such that it moves with constant velocity 
Constant velocity implies that net force on the box is zero
i.e. there must be an opposing force which is equal to the applied force and friction force can serve that purpose.
So option c is the correct choice.
Answer:
2420 J
Explanation:
From the question given above, the following data were obtained:
Force (F) = 22.9 N
Angle (θ) = 35°
Distance (d) = 129 m
Workdone (Wd) =?
The work done can be obtained by using the following formula:
Wd = Fd × Cos θ
Wd = 22.9 × 129 × Cos 35
Wd = 22.9 × 129 × 0.8192
Wd ≈ 2420 J
Thus, the workdone is 2420 J.
Answer:
Explanation:
Speed of skier without parachute
= √ 2gh
= √ 2 x 9.8 x 35
= 26.2 m / s
Speed of skier with parachute
net force downwards
mg - 200
= 60 x 9.8 -200
= 388 N
acceleration = 388 / 60
a = 6.47 m / s
v = √ 2ah
= √ 2 x 6.47 x 35
= 21.28 m / s
Answer:
55%
Explanation:
take efficiency=power output/power input multiply by 100%
