Answer:
Explanation:
(a) The velocity of object is zero when it is at maximum height.
(b) The direction of velocity changes as it starts moving downwards after it reaches the maximum height.
(c) Acceleration due to gravity always acts downwards so its sign remains same.
Answer:

Explanation:
Given,
mass of the object,m = 0.30 Kg
initial speed, v_i = 3 m/s
time of collision = 0.20 s
final speed, v_f = -4 m/s
Impulse = change in momentum



Hence, impulse of the object is equal to 
Answer:
The magnetic field strength and the electrons' energy are 0.077 T and 0.8906 eV.
Explanation:
Given that,
Diameter = 2.62 mm
Frequency = 2.15 GHz
(A). We need to calculate the magnetic field strength
Using formula of the magnetic field strength

Where, f = frequency
e = charge of electron
Put the value into the formula


(B). We need to calculate the energy of electron
Using formula of energy



The energy in eV



Hence, The magnetic field strength and the electrons' energy are 0.077 T and 0.8906 eV.
bonded pairs of electrons, lone pairs of electrons.
The answer is <span>C. 49 m/s
The kinetic equation is:
v2 = v1 + a * t
v1 - initial velocity
v2 - final velocity
a - gravitational acceleration
t - time
We know:
v2 = ?
v1 = 0 (in free fall
a = 9.8 m/s
t = 5
</span>v2 = v1 + a * t
v2 = 0 + 9.8 * 5
v2 = 0 + 49
v2 = 49 m/s