A hypothesis is an educated prediction that can be tested.
When the temperature lowers the plants can freeze and die. One way to prevent that is to cover the plants so they dont freeze
Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum

and making
the subject then
and since
is initial velocity of car, value given as 4 m/s,
is the initial velocity of the three cars stuck together, value given as 2 m/s and
is the final velocity which is unknown. By substitution

(b)
Initial kinetic energy is given by

Final kinetic energy is given by

The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ
Answer:
2.03 x 10²⁴N
Explanation:
Given parameters:
Mass of moon = 7.34 x 10²²kg
Mass of the earth = 5.97 x 10²⁴kg
Distance = 3.8 x 10⁵km
Unknown:
Gravitational force of attraction = ?
Solution:
To find the gravitational force of attraction between the masses, we use the expression below;
F =
G is the universal gravitation constant
m is the mass
1 and 2 represents moon and earth
r is the distance
F =
F =
= 2.03 x 10²⁴N
Answer: sound waves or cosmic rays
Explanation:
Cosmic radiation consist of high energy particles,x-rays and gamma rays produce in space