Which does not decrease your chances of being injured

Define fundamental and derived quantities with two example of each.

stich3 [128]

Fundamental quantity : quantities which are independent on other physical quantity .

ex: length,mass,time, current, amount of substance, luminous intensity, thermodynamic temperature,

Derived quantity : quantities which are depend on fundamental quantities.

ex: Area, volume, density, speed, acceleration, force, velocity etc.

4 0

2 years ago

A boat is traveling with a velocity of 18 meters/second relative to water and the river is flowing at a velocity of 2.5 meters/s

ddd [48]

Vt = Vboat - Vriver
Vt = 18 - 2.5 = 15.5 m/s

If the boat's direction is the same as the water, you sum the velocities of the river and the boat .

8 0

3 years ago

Read 2 more answers

A block of mass 500g is pulled from rest on ahorizontal frictionless bench by a steady force F and travels 8m in 2s find the acc

Korvikt [17]

We are Given:

Mass of the block (m) = 500 grams or 0.5 Kg

Initial velocity of the block (u) = 0 m/s

Distance travelled by the block (s) = 8 m

Time taken to cover 8 m (t)= 2 seconds

Acceleration of the block (a) = a m/s²

Solving for the acceleration:

From the seconds equation of motion:

s = ut + 1/2* (at²)

replacing the variables

8 = (0)(2) + 1/2(a)(2)²

8 = 2a

a = 4 m/s²

Therefore, the acceleration of the block is 4 m/s²

3 0

3 years ago

What is the current in a series circuit with a resistance of 30 ohms and a potential difference of 120 volts?

mars1129 [50]

0.25A....................

7 0

3 years ago

A 500 W hair dyer is used to dry hair for 6 minutes a day for 3 days. How much energy is used? A laptop uses 75 W. The cot of el

zzz [600]

Answer:

See the answers below.

Explanation:

We will solve this problem by calculating each part separately.

A 500 W hair dyer is used to dry hair for 6 minutes a day for 3 days.

Energy can be calculated by multiplying the value of the power of the equipment by the amount of time of use.

$500 [W]*[\frac{6min}{1day} ]*[\frac{1day}{24hr} ]*[\frac{1hr}{60min} ]=2.083 [W]$

The cots of electricity is 5.6 cents per kWh. How much would it cost to operate the laptop for 24 hours a day for one week?

We know that the power of the latop is 75 [W], then we can calculate the cost, multiplying the value of the power by the value of the cost by the time of use of the computer.

$0.075[kW]*5.6[\frac{cents}{kw*h}}]*[\frac{24hr}{1day}]*[1week]*[\frac{7days}{1week} ]=70.56 [cents]$

A toaster oven is 85% efficient. It uses 1200 J of energy. How much thermal energy is it producing?

Efficiency is defined as the relationship between the energy obtained on the energy delivered. Almost always the energy delivered is greater than the energy obtained (first law of thermodynamics).

Therefore.

$Effic = E_{obtained}/E_{delivered}\\0.85=E_{obtained}/1200\\E_{obtained}=1020[J]$

4 0

3 years ago