Answer:
a. 60.5 kg
Explanation:
Given data,
The maximum water a boat can displace is, 60.5 ml
According to the principle of buoyancy, the weight of the floating body is equal to the weight of the liquid displaced.
Under standard temperature and pressure, a unit mass of water equals one liter.
If a boat can displace a maximum of 60.5 ml of water, then it can hold a mass of a maximum of 60.5 kg of mass.
Answer:
B.) by interfering with sound waves
Explanation:
As we know that the interference of sound waves is of two types
1). constructive interference
2). destructive interference
now we know that constructive interference means the resultant intensity will be more than the intensity of interfering waves as here two waves are in same phase.
In destructive interference the resultant of two waves is given by the minimum resultant of the intensity as here the phase of two waves are opposite to each other.
So we will say that
here in case of noise cancelling headphones we know that the phase of noise is always made in opposite phase with the sound which is used to cancelled the noise.
This will reduce the noise and we will get a clear sound
watts = work per second.
work is mgh = 3x10x50=1500
watts out = 1500
Watts used = 2000
eff=1500/2000=75%
Answer:
The material with higher modulus will stretch less than
The material with lower modulus
Explanation:
A material with a higher modulus is stiffer and has better resistance to deformation. The modulus is defined as the force per unit area required to produce a deformation or in other words the ratio of stress to strain.
E= stress/stain
Hooks law states that provided the elastic limit is not exceeded the extension e of a spring is directly proportional to the load or force attached
F=ke
Where k is the constant which gives the measure of the spring under tension
The answer is A. Friction
hope this helps :)
