Airports use ramps to connect the plane to the airport and towing trucks use ramps to get the vehicles on the truck
"700 watts" means 700 joules of work per second.
"300 watts" means 300 joules of work per second.
If the labels on both machines are true, and both machines
are loaded to their full capacity, then the 700-watt engine
is doing work faster than the 300-watt one.
The net force is the sum of the forces acting on an object ( chair ).
F net = F 1 + F 2
F 1 = 20 N, F 2 = - 12 N
F net = 20 N + ( - 12 N ) = 8 N
The chair will tend to move to the left.
The frequency (f) in hertz (1/s) of the sound waves is the quotient when its speed (S) is divided by the wavelength (n). This is mathematically expressed,
f = S / n ; f = (331 m/s) / (0.6 m) = 551.67 / s
Thus, the frequency of the wave is 551.67 Hz.
Answer:
A. 231.77 J
B. 5330.71 J
C. 46 donuts
Explanation:
A. To lift the barbell once, she will have to extend it the full length of her arm. The work done will then be:
W = F * d
Where the force is the weight of the barbell.
F = m * g
Hence, the work done in lifting the barbell is:
W = m * g * d
W = 43 * 9.8 * 0.55
W = 231.77 J
B. If she does 23 repetitions, the total energy she expend will be equal to the Potential energy when the barbell is lifted multiplied by 23:
E = 23 * m * g * d
E = 23 * 231.77
E = 5330.71 J
C. 1 Joule = 4.184 calories
5330.71 Joules = 5330.71 * 4.184 = 22303.69
If 1 donut contains 490 calories, the number of donuts she will need will be:
N = 22303.69/490 = 45.5 donuts or 46 donuts
