Answer :
The frictional force on the block from the floor and the block's acceleration are 10.45 N and 0.73 m/s².
Explanation :
Given that,
Mass of block = 3.50
Angle = 30°
Force = 15.0 N
Coefficient of kinetic friction = 0.250
We need to calculate the frictional force
Using formula of frictional force





(II). We need to calculate the block's acceleration
Using newton's second law of motion





Hence, The frictional force on the block from the floor and the block's acceleration are 10.45 N and 0.73 m/s².
Answer:
v = 10.84 m/s
Explanation:
using the equation of motion:
v^2 = (v0)^2 + 2×a(r - r0)
<em>due to the hammer starting from rest, vo = 0 m/s and a = g , g is the gravitational acceleration.</em>
v^2 = 2×g(r - r0)
v = \sqrt{2×(-9.8)×(4 - 10)}
= 10.84 m/s
therefore, the velocity at r = 4 meters is 10.84 m/s
Given Information:
Diameter of spherical cell = 0.040 mm
thickness = L = 9 nm
Resistivity = ρ = 3.6×10⁷ Ω⋅m
Dielectric constant = k = 9.0
Required Information:
time constant = τ = ?
Answer:
time constant = 2.87×10⁻³ seconds
Explanation:
The time constant is given by
τ = RC
Where R is the resistance and C is the capacitance.
We know that resistivity of of any material is given by
ρ = RA/L
R = ρL/A
Where area of spherical cell is given by
A = 4πr²
A = 4π(d/2)²
A = 4π(0.040×10⁻³/2)²
A = 5.026×10⁻⁹ m²
The resistance becomes
R = (3.6×10⁷*9×10⁻⁹)/5.026×10⁻⁹
R = 6.45×10⁷ Ω
The capacitance of the cell membrane is given by
C = kεoA/L
Where k = 9 is the dielectric constant and εo = 8.854×10⁻¹² F/m
C = (9*8.854×10⁻¹²*5.026×10⁻⁹)/9×10⁻⁹
C = 44.5 pF
C = 44.5×10⁻¹² F
Therefore, the time constant is
τ = RC
τ = 6.45×10⁷*44.5×10⁻¹²
τ = 2.87×10⁻³ seconds
Answer:
0.36 kg-m/s
Explanation:
Given that,
Mass of a ball, m = 0.06 kg
Initial velocity of the ball, u = 20 m/s
Final velocity of the ball, v = 26 m/s
We need to find the change in momentum of the tennis ball. It is equal to the final momentum minus initial momentum

So, the change in momentum of the ball is 0.36 kg-m/s.
Explanation:
It represents the direction of flow of positive charge but is treated as a scalar quantity because current follows the laws of scalar addition and not the laws of vector addition. The angle between the wires carrying current does not affect the total current in the circuit.