Answer:
Explanation:
Frictional force acting on the child = μ mg cosθ
, μ is coefficient of kinetic friction , m is mass of child θ is inclination
work done by frictional force
μ mg cosθ x d , d is displacement on inclined plane
work done = .13 x 276 x cos34 x 5.9
= 175.5 J
This work will be converted into heat energy.
b ) Initial energy of child = mgh + 1/2 m v ² , h is height , v is initial velocity
= 276 x 5.9 sin34 + 1/2 x 276 / 9.8 x .518² [ mass m = 276 / g ]
= 910.59 + 3.77
= 914.36 J
loss of energy due to friction = 175.5
Net energy at the bottom
= 738.86 J
If v be the velocity at the bottom
1/2 m v² = 738 .86
.5 x (276 / 9.8) x v² = 738.86
v² = 52.47
v = 7.24 m /s .
You would need to ear defenders (I'm assuming these are ear protectors for use with loud sounds) while firing at a gun range. You could use it for loud construction areas.
Answer:
v = 112.424 km / s
Explanation:
Given:
d = 3.84 x 10 ⁸ m , R = 63 x 10³ m , m earth = 5.97 x 10²⁴ kg , G = 6.67 x 10⁻¹¹ N * m² / kg² , v₁ = 14.8 x 10 ³ m / s
Using the equation
KE + PE = initial KE + PE
¹/₂ * m * v₂² - G * m/ R = ¹/₂ * m * v₁² - G * m/(R+d)
v₂² = v₁² + 2*G * m [ 1/R - 1/(R+d) ]
v₂² = 14.8 x 10 ³ m /s + 2 * 6.67 x 10⁻¹¹ N * m² / kg² * 5.97 x 10²⁴ kg [ 1 / 63 x 10³m - 1 / ( 63 x 10³ + 3.84 x 10⁸ m ) ]
v = √ 1.26 x 10¹⁰ m² / s²
v = 112.424 x 10³ m/s
v = 112.424 km / s
Answer:
the normal force
Explanation:
The free-body diagram represents all the forces acting on an object. In this example, there are four forces acting on the box: an applied force, the friction (which always act opposite to the applied force), the weight of the box (which is always downward), and the normal force.
The normal force is the reaction force exerted by the surface on which the box is moving on the box, and this reaction force is always opposite to the force exerted by the box on the surface. Since the latter is downward, it means that the normal force must be upward, so in the diagram it is wrong.
Answer:
Negative
Explanation:
If a negatively charged object is used to charge a neutral object by induction, then the neutral object will acquire a positive charge. And if a positively charged object is used to charge a neutral object by induction, then the neutral object will acquire a negative charge:
We have a neutral sphere
1) Electrons are attracted to the positive charge
2) Electrons enter the sphere from ground, attrated to the + charge in the sphere
3) The sphere has an excess of e- having entered from the ground
4) Electrons redistribute uniformly