Answer:
Explanation:
mass of backpack, m = 8.1 kg
weight of climber, W = 656 N
height raised, h = 9.4 m
time, t = 28.2 min = 28.2 x 60 = 1692 second
weight of backpack, w = m x g = 8.1 x 9.8 = 79.38 N
Work done by the climber on the backpack = mg x h = 79.38 x 9.4 = 746.17 J
Wok done in lifting herself + backpack = (W + w) x h
= (656 + 79.38) x 9.4 = 6912.57 J
Power developed by the climber,P = Total work / time
P = 6912.57 / 1692 = 4.09 W
Answer:
The coefficient of static friction between the box and floor is, μ = 0.061
Explanation:
Given data,
The mass of the box, m = 50 kg
The force exerted by the person, F = 50 N
The time period of motion, t = 10 s
The frictional force acting on the box, f = 30 N
The normal force on the box, η = mg
= 50 x 9.8
= 490 N
The coefficient of friction,
μ = f/ η
= 30 / 490
= 0.061
Hence, the coefficient of static friction between the box and floor is, μ = 0.061
Answer:
B
Explanation:
Laboratories are usually controlled: however, in public places, there are way too many factors that could change an experiment
B. A small rubber ball bouncing near a little girl
Answer:
Into the page
Explanation:
According to Fleming's hand rule, the middle finger represent the direction of the current, the forefinger represents that of the magnetic field and the thumb gives the direction of the force. when you hold out your left hand with the forefinger, middle finger and thumb at the right angle to one another as the thumb points upward the middle finger will point rightward and the forefinger will point in the direction into the paper.
