Answer:
Less than 1 m
Explanation:
When objects are getting closer to each other there is a slight change in the wavelength that is being transmitted by either objects. This is known as the blue shift of waves. Here, the wavelength reduces.
In the opposite case the when objects are getting farther from each other there is a slight change in the wavelength that is being transmitted by either objects. This is known as the red shift. Here, the wavelength increases.
In this case the spaceship is getting close to Earth hence the wavelength will be lower than 1 m.
But we do not know whether the force is pushing or pulling (the same direction (both forces are parallel) but: .........[ ]<-F-- or .......[ ]--F-->). I suppose the correct answer is B
Answer: The ball (option A)
Explanation: change in momentum is defined by the formulae m(v - u) where m = mass of object, v = final velocity and u = initial velocity.
For the ball, it hits the ground and bounces back with the same speed, that's final velocity equals initials (v = - u)
Change in momentum = m( -u- u) = m(-2u) = m(-2u) = -2mu
For the clay, it final velocity is zero since it sticks to the floor, hence (v =0)
m(v - u) = m(0 - u) = - mu.
-2mu (change in momentum from the ball) is greater than - mu ( change in momentum of clay)
When cooking food in a microwave it is more important to rely on the internal temperature of the food because microwave do not adequately kills pathogens that may be in food. Microwave normally penetrate food to the depth of 1 to 1.5 only. In thicker foods, microwave doesn't usually reach the center of the food, the un-reached part normally cook by conduction.
