Answer:
A) t = 4.40 s
, B) v = 23.86 m / s
, c) v_y = - 43.12 m / s
, D) v = 49.28 m/s
Explanation:
This is a projectile throwing exercise,
A) To know the time of the stone in the air, let's find the time it takes to reach the floor
y = y₀ +
t - ½ g t²
as the stone is thrown horizontally v_{oy} = 0
y = y₀ - ½ g t²
0 = y₀ - ½ g t²
t = √ (2 y₀ / g)
t = √ (2 95 / 9.8)
t = 4.40 s
B) what is the horizontal velocity of the body
v = x / t
v = 105 / 4.40
v = 23.86 m / s
C) The vertical speed when it touches the ground
v_y =
- g t
v_y = 0 - 9.8 4.40
v_y = - 43.12 m / s
the negative sign indicates that the speed is down
D) total velocity just hitting the ground
v = vₓ i ^ + v_y j ^
v = 23.86 i ^ - 43.12 j ^
Let's use Pythagoras' theorem to find the modulus
v = √ (vₓ² + v_y²)
v = √ (23.86² + 43.12²)
v = 49.28 m / s
we use trigonometry for the angle
tan θ = v_y / vₓ
θ = tan⁻¹ (-43.12 / 23.86)
θ = -61
Answer:
(a) Potential energy of the child is converted into the kinetic energy at the bottom off the slide and a part of which is lost into friction generating heat between the contact surfaces.
(b) 
Explanation:
Given:
- mass of the child,

- height of the slide,

- initial velocity of the child at the slide,

- final velocity of the child at the bottom of slide,

(a)
∴The initial potential energy of the child is converted into the kinetic energy at the bottom off the slide and a part of which is lost into friction generating heat between the contact surfaces.
Initial potential energy:



Kinetic energy at the bottom of the slide:



(b)
Now, the difference in the potential and kinetic energy is the total change in the thermal energy of the slide and the seat of her pants.
This can be given as:



Answer:
Attractive Property – Magnet
Explanation:
attracts ferromagnetic materials like iron, cobalt, and nickel. Repulsive Properties – Like magnetic poles repel each other and unlike magnetic poles attract each other. Directive Property – A freely suspended magnet always points in a north-south direction.
Answer:
a) F=20287.22N
b) t=2*10^-4s
Explanation:
E=1/2*m*v^2=0.5*7.8*10^-3kg*(530m/s)^2=1095.51J
The frictional force's work must be equal than the energy to stop the bullet.
So: W=F*d=F*0.054m=1095.51J, F=20287.22N
Considering the frictional force is constant, the bullet moves with constant aceleration.
a=F/m=20287.22N/7.8*10-2kg=2.6*10^6m/s^2
then d(t)=Vt-1/2*a*t^2,
5.4*10^-2m=530m/s*t-1.3*10^6m/s^2*t^2
I will calculate the time using the cuadratic formula:

with a=1.3*10^6, b=-530, c=5.4*10^-2
t=2*10^-4s
Solar energy is energy that is produced using the sun's rays.