Answer:
a.) L = 2.64 kgm^2/s
b.) V = 4.4 m/s
Explanation: Jessica stretches her arms out 0.60 m from the center of her body. This will be considered as radius.
So,
Radius r = 0.6 m
Mass M = 2 kg
Velocity V = 1.1 m/s
Angular momentum L can be expressed as;
L = MVr
Substitute all the parameters into the formula
L = 2 × 1.1 × 0.6 = 1.32kgm^2s^-1
the combined angular momentum of the masses will be 2 × 1.32 = 2.64 kgm^2s-1
b. If she pulls her arms into 0.15 m,
New radius = 0.15 m
Using the same formula again
L = 2( MVr)
2.64 = 2( 2 × V × 0.15 )
1.32 = 0.3 V
V = 1.32/0.3
V = 4.4 m/s
Her new linear speed will be 4.4 m/s
Answer:
The gravitational acceleration of the planet is, g = 8 m/s²
Explanation:
Given data,
The distance the object falls, s = 144 m
The time taken by the object is, t = 6 s
Using the III equations of motion
S = ut + ½ gt²
∴ g = 2S/t²
Substituting the given values,
g = 2 x 144 /6²
= 8 m/s²
Hence, the gravitational acceleration of the planet is, g = 8 m/s²
Answer:
Displacement method of volume measurement is no suitable
Explanation:
Displacement method of volume measurement is no suitable for the objects that do not get immersed into the water completely because of the hindrance in accuracy of the measurement.
Answer:
B. Objects do not have to touch each other to experience a force.
Explanation:
For example ..One of the noncontact forces is magnetic force whereby a magnetic object will be attracted to another magnetic object of oppsite charged particles, through waves called electromagnetic waves. On the other hand, the two magnetic objects of similar charged particles can repel through electromagnetic waves..
Answer:
10500 J/kg/*C
Explanation:
Quantity of heat required=mass of substance x specific heat capacity x change in temperature
Quantity of heat required=0.25 x 4200 x [30-20]
Quantity of heat required=0.25 x 4200 x 10
Quantity of heat required=10500 J/kg/*C
