Answer:
The skater's speed after she stops pushing on the wall is 1.745 m/s.
Explanation:
Given that,
The average force exerted on the wall by an ice skater, F = 120 N
Time, t = 0.8 seconds
Mass of the skater, m = 55 kg
It is mentioned that the initial sped of the skater is 0 as it was at rest. The change in momentum of skater is :
The change in momentum is equal to the impulse delivered. So,
So, the skater's speed after she stops pushing on the wall is 1.745 m/s.
Answer:
i hope this will help you :)
Explanation:
mass=19kg
density=800kg/m³
volume=?
as we know that
density=mass/volume
density×volume=mass
volume=mass/density
putting the values
volume=19kg/800kg/m³
so volume=0.02375≈0.02m³
Unlike acceleration and velocity, speed does not need to specify the direction of motion. Speed is a scalar quality.
Answer:
F4.0
Explanation:
To obtain a shutter speed of 1/1000 s to avoid any blur motion the f-number should be changed to F4.0 because the light intensity goes up by a factor of 2 when the f-number is decreased by the square root of 2.
Answer:
The value of the linear coefficient of thermal expansion is : α=1.01 *10⁻⁵ (ºC)⁻¹
Explanation:
Li = 0.2m
ΔL = 0.2 mm = 0.0002m
T1 = 21ºC
T2 = 120ºC
ΔT =99ºC
α =ΔL/(Li*ΔT)
α =0.0002m /(0.2m * 99ºC)
α = 1.01 *10⁻⁵ (ºC)⁻¹
